The East Mission Flats Repository is west of Cataldo, Idaho, across Interstate 90, away from the Old Mission. The repository securely contains contaminated soils from property cleanups in the Lower Basin. It helps reduce people's exposure to harmful metals like lead and arsenic. Property owners who do their own work under the Basin Institutional Controls Program can also dispose of soils at East Mission Flats.

In response to public input, the repository height has been reduced from 62 feet to 34 feet. East Mission Flats is not easily visible from the Old Mission. Only soils contaminated with mine waste are accepted at the repository. Municipal wastes and residential garbage are not accepted.

Superfund cleanup is being conducted in the Coeur d'Alene Basin to address unacceptable health risks to people and the environment. Soils from cleanups of residential and commercial properties contain metals, like lead and arsenic, that can harm people. These soils need a place to go to be safely contained. Waste repositories are carefully chosen and engineered to securely contain contaminated soils through time, to reduce impacts to people and the environment. Repositories will be managed long after they are closed to be sure the contaminants remain contained and secure.

Floodwater Monitoring at the East Mission Flats Repository (PDF) (51 pp, 6.7MB) - March 2014. This document contains the results of the March 2014 floodwater monitoring at the East Mission Flats Repository. The results conclusively show that floodwater lead concentrations decreased as floodwater left the area surrounding the repository. The results for cadmium and zinc are inconclusive. Based on the lack of correlation between floodwater metals concentrations and the migration of dissolved metals away from the repository, the floodwater monitoring will be discontinued at the East Mission Flats Repository. Due to the extensive contamination in the area, changes in floodwater metals concentrations can be influenced by many sources unrelated to the repository making the monitoring ineffective for the detection monitoring program required at the repository. However, all monitoring, including groundwater and repository pore water monitoring that were included as part of the Enhanced Monitoring Plan accepted by the EPA Office of Inspector General will be continued.

Monitoring results (PDF) (2 pp, 90K) available for dissolved metals in groundwater at the East Mission Flats Repository, for Dec. 2007 - Nov. 2009. In response to the EPA Office of Inspector General's recommendation, the Idaho Dept. of Environmental Quality and EPA committed to an Enhanced Monitoring Plan (EMP) (PDF) (17 pp, 874K) for the repository. After field equipment is installed in Summer 2010, the agencies will collect and post the other data we committed to under the EMP. This will include tragmnsducer and manual water levels, USGS Cataldo gauging station data, and water quality data. View EMP summary (PDF) (2 pp, 29K).